Antarctic ice sheets may have changed the planet’s heartbeat

One skipped beat shifted ice ages from 40,000 year cycles to 100,000 year ones.

You may have seen them before—the graphs from Antarctic ice cores showing the heartbeat of “ice ages” (or glaciations). If so, you probably noted a cyclical pattern, with each glaciation lasting about 100,000 years before being abruptly interrupted by a relatively brief warm period—the interglacial. Soon, the slow freeze inexorably gripped the planet again. There's a reason for this rhythmic pattern—cycles in Earth’s orbit that subtly alter the sunlight reaching the Earth.

But the graphs have long contained a couple head-scratching mysteries to climate scientists, though. First, why is the 100,000 year cycle dominant? There are several orbital cycles—some around 20,000 years long, another about 41,000 years long, and then the 100,000 year cycle. By itself, the 100,000 year cycle changes things the least, yet it drives the glacial heartbeat.

Enlarge/ Glacial cycles experienced a sudden change in behavior at 400,000 years ago.

Wikimedia Commons

There are some good answers to that question, but then there’s the other mystery: once you look back about a million years into the past, the heartbeat changes. Instead of glacial cycles 100,000 years long, a more rapid pulse of 41,000 years becomes the norm. Something happened to change that. Here, too, there are some hypotheses, but the data to test them has been scarce.

Enter a new study from researches at the University of Cambridge. The study presents 1.5 million years of climate history recorded in ocean sediments off the eastern shore of New Zealand. As with most ocean cores, the team measured isotopes of oxygen in the calcium carbonate shells of single-celled foraminifera. (The same isotopes are used to extract climate records from ice cores.)

While those cores are astonishing libraries of climate history, they are complicated by the fact that the oxygen isotopes in those shells are tracking more than one variable. The amount of water that ends up trapped in ice sheets on the continents (lowering sea level) alters the isotopic ratio in the ocean. This means that changes in the record indicate changes in the volume of ice present on the planet. At the same time, the temperature of the ocean water affects the chemistry of the foraminifera’s shell growth, and this affects the isotopic signature as well.

One way to account for this confusion is to find a separate proxy that only records temperature. The ratio of magnesium to calcium (magnesium can take the place of calcium in carbonate shells) does just that. When you subtract the effect of temperature change from the oxygen isotope signal, you’re left with only one thing: ice volume.

This isn’t a new technique, but its application to the transition from 41,000 year glacial cycles to 100,000 year ones makes this record very valuable. Researchers studying the transition have mostly had to do so through smudged lenses—using climate records that couldn’t differentiate between temperature change and ice sheet behavior.

Existing records generally indicate that the transition was gradual, phasing in over a period of 500,000 years or so as glaciations grew colder. In contrast, this new record shows no trend in temperature and a sudden transition in ice volume, which hit a new maximum 900,000 years ago. Glaciations flipped into a different mode from then on.

While the details of this study may be different, it's not the first to provide evidence that ice sheets grew larger during this time. This growth is the best explanation available for the change to 100,000 year glacial cycles. Beyond a certain size, ice sheets become more stable in some ways—the high altitude region of the ice sheet sticks its head into cooler air at higher elevation, for example. Larger ice sheets could withstand the orbital warming nudge that previously ended glaciations after 41,000 years.

The most likely candidates for that increase in ice sheet volume have been the Northern Hemisphere ice sheets, but this new study proposes that the critical change may have occurred in Antarctica. The record reflects ocean conditions near Antarctica, whereas the coverage of other ocean sediment cores covering this timeframe have been biased toward the North Atlantic. Since the new record differs from the others, it suggests the Antarctic ice sheet were not marching in step with the Northern Hemisphere ice sheets.

And there’s good reason to think that the Antarctic ice sheet could have “gone rogue.” The rise in incoming solar radiation at the end of the 41,000 year period just prior to the increase in ice volume was very weak, which could have allowed the Antarctic ice to skip the usual melt, and then grow to a new maximum size. (Because it’s summer solar radiation that matters, orbital changes for the two hemispheres are not synchronized— only the Southern Hemisphere experienced these unusual conditions.) After skipping that beat, the researchers think this larger Antarctic ice sheet could have guided the climate into the 100,000 year groove.

In a perspective published in the same issue of Science, Oregon State’s Peter Clark writes, “Confirmation of these hypotheses will require generation of similar-quality… data sets, which should help to better understand the range of regional variability in deep-ocean temperature and [oxygen isotope signature].” Are there other explanations for the pattern seen in this climate record? Answering that question will require more ice volume records from more locations, each of which will dispel a bit more of the mystery surrounding this pivotal transition in Earth’s climate system.

What about Geomagnetic reversal? The last one occurred ~780,000 years ago and could have had an enormous impact on these 41k/100k glacial cycles. A polar flip would make Antarctica the Arctic and visa-versa, causing sunlight concentrations to reflect differently due to the differences in ice, water and land shifting locale.

QUOTE: "...but then there’s the other mystery: once you look back about a million years into the past".

What about Geomagnetic reversal? The last one occurred ~780,000 years ago and could have had an enormous impact on these 41k/100k glacial cycles. A polar flip would make Antarctica the Arctic and visa-versa, causing sunlight concentrations to reflect differently due to the differences in ice, water and land shifting locale.

QUOTE: "...but then there’s the other mystery: once you look back about a million years into the past".

What about Geomagnetic reversal? The last one occurred ~780,000 years ago and could have had an enormous impact on these 41k/100k glacial cycles. A polar flip would make Antarctica the Arctic and visa-versa, causing sunlight concentrations to reflect differently due to the differences in ice, water and land shifting locale.

QUOTE: "...but then there’s the other mystery: once you look back about a million years into the past".

Seems to coincide with a polar/geomagnetic reversal to me!

The only things that flip in a geomagnetic reversal are the magnetic poles; your compass starts pointing towards Antarctica, but that's about it. The physical poles don't move.

My thoughts are that there might have a new waterway movement, maybe Indonesia waterway, the water had to go around Australia and that added warm water to the current around Antarctica? This would not affect the north but change the south.

It would have been helpful to mention briefly what the 20 (isn't it 21?) / 41 / 100K year orbital cycles are about instead of having to look it up, so we understand why the 100,000 year cycle could be nullified by the cooler Earth temperature but the not the 41,000 year cycle.

It would have been helpful to mention briefly what the 20 (isn't it 21?) / 41 / 100K year orbital cycles are about instead of having to look it up, so we understand why the 100,000 year cycle could be nullified by the cooler Earth temperature but the not the 41,000 year cycle.

I've added a wiki link to the first para. I had forgotten to do that.

It's complicated because there are actually several cycles around 20,000 years long... I try to keep it simple.

The response to the 100,000 warming after growing past the 41,000 warming is also up in the air. It might be that a bigger ice sheet generates bigger feedbacks, which would counterintuitively make very large ice sheets less stable again, in a way.

What about Geomagnetic reversal? The last one occurred ~780,000 years ago and could have had an enormous impact on these 41k/100k glacial cycles.

It is possible it contributed. The geomagnetic field that surrounds the planet is critical in protecting the planet from cosmic radiation, and further out are the Van Allen radiation belts.

So, the magnetic flipping could play havoc with the protection fields, causing less radiation to reach the planet (trigger ice age), or more (ice age... you've been voted off the planet).

This has been looked at in relation to Svensmark's "cosmic ray" climate theory, in which cosmic rays would supposedly seed cloud formation (thus affecting how much sunlight is reflected). The evidence doesn't bear it out. Other than cosmic rays (charged particles), I don't think the magnetic field doesn't have an appreciable effect on incoming solar radiation.

My thoughts are that there might have a new waterway movement, maybe Indonesia waterway, the water had to go around Australia and that added warm water to the current around Antarctica? This would not affect the north but change the south.

This has been looked at a lot, too. Especially the rise of Panama, cutting off exchange between the Atlantic and Pacific there, and the opening of the Drake Passage between Antarctica and South America. But those are farther in the past.

To answer my own question, in January of this year, research was published predicting that, absent the influence of humans (greenhouse gas emissions), the next ice age would begin within the next 1500 years.

However, as it now stands, a few more thousand years will pass before the next ice age because of the time required for A) all fossil fuels to be burned and B) all of the resulting carbon dioxide to be naturally removed from the atmosphere.

So, places like Berlin, Toronto, Chicago, etc. will be ice free until at least 5000 A.D. However, by 7000 A.D., they're likely to be covered in glaciers.

Any idea what the orbital period of our solar system is through the Milky Way? Wonder if that has any correlation to any of the cycles...

Is there anything that could be measured to determine where our star has been? I can't help thinking it would vary wildly, particularly given the amount of time it would take for a full 'orbit' - tens of millions of years?

To answer my own question, in January of this year, research was published predicting that, absent the influence of humans (greenhouse gas emissions), the next ice age would begin within the next 1500 years.

However, as it now stands, a few more thousand years will pass before the next ice age because of the time required for A) all fossil fuels to be burned and B) all of the resulting carbon dioxide to be naturally removed from the atmosphere.

Ah yes, one of the unsung benefits of CO2 emission (along with increased food production). A bit of fortuitous, accidental geoengineering, eh?

Quote:

So, places like Berlin, Toronto, Chicago, etc. will be ice free until at least 5000 A.D. However, by 7000 A.D., they're likely to be covered in glaciers.

Actually, as long as we don't descend into a new Dark Age it's very unlikely that will happen. Intentional geoengineering will intervene.

This has been looked at in relation to Svensmark's "cosmic ray" climate theory, in which cosmic rays would supposedly seed cloud formation (thus affecting how much sunlight is reflected). The evidence doesn't bear it out.

That remains to be seen. There have only been a couple of preliminary studies so far. I'm surprised you didn't employ more cautious language when discussing a scientific theory. To climate science aficionados, all science is "settled" I guess.

Other than cosmic rays (charged particles), I don't think the magnetic field doesn't have an appreciable effect on incoming solar radiation.

I believe you meant to say "I think the magnetic field doesn't" instead of a double negative...

The other major influence on cosmic radiation influx is the solar wind, which dies down dramatically during solar minima - which will likely be a dominant condition for the next thirty years or longer.

It may be just a coincidence that global temperatures dipped dramatically during the Maunder and Dalton solar grand minima, but I wouldn't bet on it.

On the other hand, there are some odd coincidences for sure - for instance a major drought in Middle America during the current economic downturn, reminiscent of the Dust Bowl years in the middle of the Great Depression.

This has been looked at in relation to Svensmark's "cosmic ray" climate theory, in which cosmic rays would supposedly seed cloud formation (thus affecting how much sunlight is reflected). The evidence doesn't bear it out.

That remains to be seen. There have only been a couple of preliminary studies so far. I'm surprised you didn't employ more cautious language when discussing a scientific theory. To climate science aficionados, all science is "settled" I guess.

Other than cosmic rays (charged particles), I don't think the magnetic field doesn't have an appreciable effect on incoming solar radiation.

I believe you meant to say "I think the magnetic field doesn't" instead of a double negative...

The other major influence on cosmic radiation influx is the solar wind, which dies down dramatically during solar minima - which will likely be a dominant condition for the next thirty years or longer.

It may be just a coincidence that global temperatures dipped dramatically during the Maunder and Dalton solar grand minima, but I wouldn't bet on it.

On the other hand, there are some odd coincidences for sure - for instance a major drought in Middle America during the current economic downturn, reminiscent of the Dust Bowl years in the middle of the Great Depression.

Yes- sorry for the typo.

Significant lulls in the strength of [Earth's geomagnetic field (with no corresponding solar change) didn't correlate with a change in climate.

Of course, during solar minima, radiation decreases as well as shielding of galactic cosmic rays...

I hope the paper has some substantial data analysis, because just eyeballing the curves they don't seem like anything but an increasingly worse data quality. The average signal stays much the same before and after the presumed transition.

JustAdComics wrote:

Any idea what the orbital period of our solar system is through the Milky Way? Wonder if that has any correlation to any of the cycles...

Nope. There is a vertical oscillation which is ~ 60 ky IIRC, and the orbital period which is ~ 200 My. Note that these numbers should be very uncertain. None of these have been tied to climate (geology) or extinctions (biology) what I know.

ScottJohnson wrote:

goglen wrote:

c0mad0r wrote:

What about Geomagnetic reversal? The last one occurred ~780,000 years ago and could have had an enormous impact on these 41k/100k glacial cycles.

It is possible it contributed. The geomagnetic field that surrounds the planet is critical in protecting the planet from cosmic radiation, and further out are the Van Allen radiation belts.

So, the magnetic flipping could play havoc with the protection fields, causing less radiation to reach the planet (trigger ice age), or more (ice age... you've been voted off the planet).

This has been looked at in relation to Svensmark's "cosmic ray" climate theory, in which cosmic rays would supposedly seed cloud formation (thus affecting how much sunlight is reflected). The evidence doesn't bear it out. Other than cosmic rays (charged particles), I don't think the magnetic field doesn't have an appreciable effect on incoming solar radiation.

The Earth geomagnetic field does diddly-squat against cosmic rays, but it helps prevent the solar wind and especially CMEs from eroding the atmosphere. It is the Earth atmosphere that mainly blocks the remaining ~ 10 % of cosmic radiation that hasn't already been attenuated by the vast solar magnetic field between the heliopause and the inner system.*

TL;DR:

The magnetic field somewhat protects the atmosphere and especially our water by keeping hydrogen escape to a minimum. (Compare Venus without strong magnetic field - dense atmosphere but little water.)

The atmosphere protects us from all forms of radiation.

And the Sun is our mummy.

* Hence a variation in solar magnetic strength, as well as solar wind/CME flow rates, can with proper phase delay affect CR. Which is what the crackpots spin off of, despite that the climate scientists now know that solar effects can't predict the current climate change.

To answer my own question, in January of this year, research was published predicting that, absent the influence of humans (greenhouse gas emissions), the next ice age would begin within the next 1500 years.

However, as it now stands, a few more thousand years will pass before the next ice age because of the time required for A) all fossil fuels to be burned and B) all of the resulting carbon dioxide to be naturally removed from the atmosphere.

So, places like Berlin, Toronto, Chicago, etc. will be ice free until at least 5000 A.D. However, by 7000 A.D., they're likely to be covered in glaciers.

And if you believe that, I can tell you a history about Santa Claus and the source of Yule presents.

"So, it would be nice to have stronger documentation that the bipolar seesaw behavior in the past is indeed Heinrich and not non-Heinrich D/O.

Furthermore, I am among many people who have studied the Heinrich layers and tried to explain them, but we haven’t quite nailed it all down."

"So, I tend to believe the new results, they confirm what has been shown by several other studies—human-caused CO2 has a large enough effect lasting long enough that it will greatly affect the natural ice-age cycling—but I’ll listen to Peter, Andre and the others with great interest, and I don’t think this is the last word on exactly what CO2 level is needed for exactly what orbital configuration for ice-age initiation. –Richard"

"I don’t have a whole lot to add beyond Richard’s discussion, but would like to make a few points about how well we can predict the future from the analogies available to us.

[Marine isotope] Sub-stage 19c [the period that Tzadekis et al focus on] does seem one of the better analogies with our current interglacial, but the inference that our current interglacial would end within 1,500 years can be questioned on several accounts."

ai33806 wrote:

ScottJohnson wrote:

This has been looked at in relation to Svensmark's "cosmic ray" climate theory, in which cosmic rays would supposedly seed cloud formation (thus affecting how much sunlight is reflected). The evidence doesn't bear it out.

That remains to be seen. There have only been a couple of preliminary studies so far. I'm surprised you didn't employ more cautious language when discussing a scientific theory. To climate science aficionados, all science is "settled" I guess.

It is settled to the extent that AGW is the current climate science theory and all the contenders have long since fallen, yes. That doesn't mean the details aren't still discussed. But cosmic rays, or rather solar influence, is not among these, it has been conclusively ruled out as the forcing behind the observed GW.

Open-minded is the code word for "reject the accepted science". What would be its relevance on a science blog?

"Are there other explanations for the pattern seen in this climate record?"

I am guessing there are. I wish we had some method of determining how oceanic streams have changed over time and how old and consistent the current streams are. I have a feeling there are a lot of "soft" mechanisms/system dynamics going on that have a huge effect on climate.

Right. I'm not wed to Svensmark's theory, though it certainly has some elegance. We'll see how it holds up going forward, the CLOUD experiment is ongoing for instance.

It may be that there's a second phenomena that also influences cloud formation during strong solar minima - or even an unrelated, unknown effect that also helps drop temperatures.

The central point is that the temperature drop during solar Grand Minima is apparently not explicable solely given the difference in insolation. It may be that coincidental volcanic activity was the explanation during the two historical minima of interest. We'll get a chance to see over the next few decades. One can only hope that a Tambora level event won't come along to mess up the data...

* Hence a variation in solar magnetic strength, as well as solar wind/CME flow rates, can with proper phase delay affect CR. Which is what the crackpots spin off of, despite that the climate scientists now know that solar effects can't predict the current climate change.

Any reasonable person would agree that CO2 has some effect on global temperature. The big question is what is the degree of forcing, and in particular the extent of water vapor amplification. This is an area where a great deal of effort should be expended in the near term - and of course cloud formation is a crucial aspect. Despite all the hand (and model) waving from the climate alarmist side of things, we don't "know" the details with sufficient accuracy at this point. That's one of the reasons that the IPCC models have a wide range of predictions, and there is still a possibility that the reality will lie outside those predictions.

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It is settled to the extent that AGW is the current climate science theory and all the contenders have long since fallen, yes. That doesn't mean the details aren't still discussed. But cosmic rays, or rather solar influence, is not among these, it has been conclusively ruled out as the forcing behind the observed GW.

That seems quite likely, yes.

However, my interest mainly lies in the effects of the solar Grand Minimum that's currently unfolding. There's a reasonable chance it will give us a lull in temperature rise over the next few decades so we can get our geoengineering capability ramped up. It's quite clear that CO2 will rise to levels the climate alarmists call unacceptable, and all agree there's no easy or quick fix for that, if it becomes clear that those levels are in fact dangerous. Having more time to gather data and study the issue is another advantage of having a few more decades before temperatures potentially rise rapidly.

Do you dispute that CO2 will inevitably rise to at least 450 PPM by 2050? That seems unavoidable to me given the developing world's refusal to meaningfully limit CO2 production, regardless of action taken by First World countries. The First World's efforts to mitigate CO2 output have so far been laughable, we'll see how things shape up this decade.

It seems prudent to limit CO2 production to a reasonable extent. This would best be achieved in the US by a massive buildout of nuclear electricity production, first largely replacing coal, then expanding electricity production as needed going forward. The "alternative energy" approaches need to be economically competitive before widespread adoption - we shouldn't impede our energy-intense economy, we will need as much capability as possible to face all possible catastrophic scenarios.

Solar looks promising on this front as a low-density supplement to high-density centralized power production. On the other hand, the current push for wind power is likely to leave the landscape dotted with rusting memorials to fuzzy envirothink as economically sane alternatives "win".

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Open-minded is the code word for "reject the accepted science". What would be its relevance on a science blog?

So now it's the "code word" boogeyman, eh?

Having an open mind is crucial for any scientist worthy of the title.

History is littered with close-minded scientists who, sure of their theory, stridently defended it 'til death - only to have it turn out to be dead wrong in the long run. In many cases decades of potentially productive activity were thrown away.

We'll see how that applies to current "climate science" eventually. lol

"Are there other explanations for the pattern seen in this climate record?"

I am guessing there are. I wish we had some method of determining how oceanic streams have changed over time and how old and consistent the current streams are. I have a feeling there are a lot of "soft" mechanisms/system dynamics going on that have a huge effect on climate.

There actually are ways of looking at ocean circulation and currents. Neodymium is a common tracer, carbon-13 is used, as well. In fact, that was part of this paper.

Any reasonable person would agree that CO2 has some effect on global temperature. The big question is what is the degree of forcing, and in particular the extent of water vapor amplification.

It isn't that CO2 has "some effect" or that it is a big question anymore, it is settled that it is the dominant factor behind the anthropogenic global warming regime observed.

ai33806 wrote:

the climate alarmist side of things, ... So now it's the "code word" boogeyman, eh?

Having an open mind is crucial for any scientist worthy of the title.

History is littered with close-minded scientists who, sure of their theory, stridently defended it 'til death - only to have it turn out to be dead wrong in the long run. In many cases decades of potentially productive activity were thrown away.

We'll see how that applies to current "climate science" eventually. lol

Code word or recognizable strawman, as your Galileo defense of all crackpots including those who reject science. The climate science is unanimous, and it isn't "alarmist" or "close-minded" to accept what has been well tested.

So I would like to ask you again, why you are trying to "discuss" science on a science blog. We who are interested in the actual science couldn't be less interested in discussing anti-science "sides".

Alas, I have been feeding a denialist troll so I won't do that. But at least I dragged him or her out for all to see. As always, reading science denialists on science blog is hilarious, so thanks for the unintentional humor it creates.

So, places like Berlin, Toronto, Chicago, etc. will be ice free until at least 5000 A.D. However, by 7000 A.D., they're likely to be covered in glaciers.

Actually, as long as we don't descend into a new Dark Age it's very unlikely that will happen. Intentional geoengineering will intervene.

That's good, as a new ice age would be a major disaster for humanity.

i'd hope that within the next 3000-5000 years, we will have perfected interplanetary (if not interstellar) travel, and will have long since colonized other planets and moons. and/or as asimov wrote about, we'll go subterranean and earth's weather won't matter anymore.

either that or the equatorial regions of earth will become massively overpopulated.

I do not understand why anyone talks about the sun when trying to explain global warming and cooling

The fact is if we only had the sun, Earth would be to cold for life; we are warmed by the decaying of the earth's radioactive core and the release of its heat into our atmosphere.

Ice ages before the advent of the Industrial Age where caused by Lake Baikal in Russia. It sits on an active ridge which intermittently spews methane gas into its botttom.

Lake Baikal up until the Industrial Age was the only place of Earth that methane could escape from the deep earth and meet fresh water at the right pressure and temperature combination.

Methane preferres its hydrate state and will do anything to retain it; it has the capability to take up to 400 degrees in heat from its surroundings to maintain its status, when it dissociates, it releases its heat all at once, methane explains both global warming and heating.

As to what's going on it the Antarctic now: Methane oxidzes to CO 2 in its final oxidization; there are great amounts of methane leaking out of weakenen oil beds. it goes to the arctic where cold temperatures complete its oxidation sequence: Methane- methanol- formalehyde and water -carbon monoxide and carbon dioxide.

The C0 2 conversion occurs after it sinks into the arctic loop that returns the water south to the Antarctic. C0 2 in the water contributes to global cooling because carbon dioxide saturated water can only freeze at 22 degrees. The Antarctic is cold enough to get it there. Once frozen it is 60 times stronger than regular ice.

Rising methane levels are the sole source of rising CO2 in the atmosphere. CO2 is the cover story for methane. In order to correct it, the oil and gas industry must fix its leaking wells and develope new techniques and drill differently, or- they must stop altogether.

Anyone who understands the propeties of methane hydrate understands that it is methane hydrate dissociation that is the sole source of global warming, not our cars and factories.

I do not understand why anyone talks about the sun when trying to explain global warming and cooling

The fact is if we only had the sun, Earth would be to cold for life; we are warmed by the decaying of the earth's radioactive core and the release of its heat into our atmosphere.

Ice ages before the advent of the Industrial Age where caused by Lake Baikal in Russia. It sits on an active ridge which intermittently spews methane gas into its botttom.

Lake Baikal up until the Industrial Age was the only place of Earth that methane could escape from the deep earth and meet fresh water at the right pressure and temperature combination.

Methane preferres its hydrate state and will do anything to retain it; it has the capability to take up to 400 degrees in heat from its surroundings to maintain its status, when it dissociates, it releases its heat all at once, methane explains both global warming and heating.

As to what's going on it the Antarctic now: Methane oxidzes to CO 2 in its final oxidization; there are great amounts of methane leaking out of weakenen oil beds. it goes to the arctic where cold temperatures complete its oxidation sequence: Methane- methanol- formalehyde and water -carbon monoxide and carbon dioxide.

The C0 2 conversion occurs after it sinks into the arctic loop that returns the water south to the Antarctic. C0 2 in the water contributes to global cooling because carbon dioxide saturated water can only freeze at 22 degrees. The Antarctic is cold enough to get it there. Once frozen it is 60 times stronger than regular ice.

Rising methane levels are the sole source of rising CO2 in the atmosphere. CO2 is the cover story for methane. In order to correct it, the oil and gas industry must fix its leaking wells and develope new techniques and drill differently, or- they must stop altogether.

Anyone who understands the propeties of methane hydrate understands that it is methane hydrate dissociation that is the sole source of global warming, not our cars and factories.

i thought cow flatulence was the main source of methane output, not a russian lake. and what does radioactivity have to do with any of this?

I do not understand why anyone talks about the sun when trying to explain global warming and cooling

The fact is if we only had the sun, Earth would be to cold for life; we are warmed by the decaying of the earth's radioactive core and the release of its heat into our atmosphere.

Way off base. We are warmed by the sun's energy being radiated from the dark Earth back up to space, but getting trapped within our atmosphere by IR-blocking gases. You're basically discounting the entire Greenhouse Effect, which explains nearly all of the temperature difference between the Earth and an atmosphere-less black body (which would, as you say, be too cold for life). By comparison, the amount of energy that escapes from radioactive decay inside the planet is teeny.

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Ice ages before the advent of the Industrial Age where caused by Lake Baikal in Russia.

That's nuts. Ice ages and glaciations are mostly a result of patterns in orbital variations over tens of thousands of years. This isn't even debatable anymore. You absolutely cannot pin millions of years of glacial/interglacial cycles on a lake in Russia, no matter how huge and deep it is.

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Rising methane levels are the sole source of rising CO2 in the atmosphere.

It surely can't be all the tens of gigatons of CO2 released by combustion every year, can it? Human emissions of CO2 are about twice as great as the average annual increase. We put more CO2 into the atmosphere than accumulates there! That means without our explicit and well-understood input the amount of CO2 would be stable or maybe even dropping, as it was for thousands of years before the Industrial Revolution.

Any reasonable person would agree that CO2 has some effect on global temperature. The big question is what is the degree of forcing, and in particular the extent of water vapor amplification.

It isn't that CO2 has "some effect" or that it is a big question anymore, it is settled that it is the dominant factor behind the anthropogenic global warming regime observed.

Ah yes, the "settled science" refrain. It reminds me of the scientists in the late 19th and early 20th century who thought they knew it all:

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"The more important fundamental laws and facts of physical science have all been discovered, and these are now so firmly established that the possibility of their ever being supplanted in consequence of new discoveries is exceedingly remote.... Our future discoveries must be looked for in the sixth place of decimals." - Albert. A. Michelson, speech at the dedication of Ryerson Physics Lab, U. of Chicago 1894

That was before nuclear energy, relativity, quantum mechanics and the much more recent but equally interesting discoveries of dark matter and dark energy.

the climate alarmist side of things, ... So now it's the "code word" boogeyman, eh?

Having an open mind is crucial for any scientist worthy of the title.

History is littered with close-minded scientists who, sure of their theory, stridently defended it 'til death - only to have it turn out to be dead wrong in the long run. In many cases decades of potentially productive activity were thrown away.

We'll see how that applies to current "climate science" eventually. lol

Code word or recognizable strawman, as your Galileo defense of all crackpots including those who reject science.

It most certainly did not, please read again more carefully.

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The climate science is unanimous, and it isn't "alarmist" or "close-minded" to accept what has been well tested.

Not a single bit of that is true. It may be that a majority of scientists believe the broad strokes of the AGW theory. However, there is considerable disagreement on the details, as well as marked differences on whether or not climactic change will be severe enough to cause major problems.

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So I would like to ask you again, why you are trying to "discuss" science on a science blog.

Truly, why would one do such a nonsensical thing?

I have a feeling you meant to phrase that rather differently.

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We who are interested in the actual science couldn't be less interested in discussing anti-science "sides".

I'm not at all anti-science, in fact science is a major interest of mine. I try and mix in also being "pro-reality".

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Alas, I have been feeding a denialist troll so I won't do that. But at least I dragged him or her out for all to see. As always, reading science denialists on science blog is hilarious, so thanks for the unintentional humor it creates.

I challenge you to find a single bit of "science denialism" in what I've written. I am an "AGW skeptic", as I remain skeptical of some of the claims of the more alarmist climate scientists. However, I'm more than willing to adjust my position going forward based on better evidence for the more extreme alarmist positions. You should also keep in mind I'm strongly advocating the one meaningful step that the US could take to reduce CO2 emissions, that being replacing coal-fired electric plants with nuclear generation. Regardless of AGW, doing that would also save many thousands of lives a year.

However, it's also worth noting that you've not addressed any of the substantive points from the post you're responding to here. Let's start with a few simple questions:

1) What is your prediction for atmospheric CO2 concentration in 2050?2) What is your prediction for atmospheric CO2 concentration in 2100?3) What assumptions underly your predictions above?

i'd hope that within the next 3000-5000 years, we will have perfected interplanetary (if not interstellar) travel, and will have long since colonized other planets and moons. and/or as asimov wrote about, we'll go subterranean and earth's weather won't matter anymore.

either that or the equatorial regions of earth will become massively overpopulated.

It's difficult to imagine that we'd be able to transport hundreds of millions or billions of people off-planet, or that they'd agree to go if there was a viable alternative. I'd say the odds are quite good that by that time they will have the wherewithal to maintain Earth as a lovely natural park without the inconvenient glaciers and mass extinctions.

We have less of everything today that is blamed for methane increases, much less than we did before methane began to increase: wetlands, forest trees, and yes . . . even cows; we reached our maximum cow herds in the 1950s.

This is how an ice age happens:

The rift under Lake Baikal, the largest and deepest and coldest lake in the world, burps methane;

The gas comes into the fresh water, grabs it and forms it's hydrate.

It can do this given the requried saturation of methane all the way to the top of the lake, and as so long as it is winter it may need not make any adjustment. If the pressure decreases below an acceptable level, it just adjusts the temperature.

When the Russian spring comes- and it warms up, methane can react to keep its water bride by taking the heat out of the air above and holding it within its sold state in the ice lattice. This maintains its associated equlibrium.

And it can hold up to 400 degree F, a wopping amount of heat, without melting the ice lattice that sits right next to the methane holding the heat.

It's a beast.

When something triggers it dissociation it releases that heat all at once It swells to 170 times its volume, if there is a chain reaction, it is quite an explosion.

One of the first scientific reports that I read on hydrates, in 2006, by British scientists, theorized that the craters in the northern reaches of Mars are the results of hydrate explosions. I agree. I think Mars was destroyed by methane hydrates

Methane hydrate can also continue to build, given the right amount of methane, into the Russian Rivers that lead to the sea, and then, once there, is even the slightest amount formed it can build into the salt water by spitting out the salt.

Please note that it can not originate in salt water; the oil and gas industry uses salt to dissociate it and keep it from clogging the flow through of oil and gas.

Methane explains all weather; it makes its hydrate in the sky also; that is what causes lightning.Andrea.